Currently, the most common user authentication methods rely on password authentication. However, passwords are easily transferable to other users and most users choose simple, short, and memorable passwords or replicate them across different accounts. This makes passwords vulnerable to dictionary attacks, brute-force, social engineering, and spyware attacks. Traditional authentication methods suffer from one-entry point (i.e., check-point) property.
Wearables such as smart watches and fitness trackers that can be carried by individuals have grown exponentially in a short period of time. It is estimated that one in four smartphone owners will also be using a wearable device such as smartwatch.